1. Field of the Invention
The present invention relates to a data receiving apparatus which is provided with a memory to store the received data and in which memory capacity is substantially increased by storing the data in the memory with high density.
2. Description of the Prior Art
In data communication units such as a facsimile apparatus of group 1 or 2 or the like which can meet the CCITT recommendation T2 or T3, there is conventionally known a unit provided with a buffer memory to store the received image data into an apparatus on the reception side. In this type of unit, a relatively large quantity of data can be transferred to the apparatus on the reception side irrespective of the processing speed of the recording apparatus at the post stage or the like; therefore, the time when the lines are used is small and there is also an advantage such that it is possible to use cheap processing apparatuses such as the recording apparatus and the like having a relatively low processing speed.
However, in the conventional data communication unit such as a facsimile apparatus of group 1 or 2 or the like, in the case of storing the received data in the buffer memory, after the received data has been demodulated and converted into binary code (hereinafter "received data" will be used to refer to the data before demodulation, and "demodulated data" to the data after demodulation, where the context does not make the meaning explicit), it is stored as is in the buffer memory, resultint in the drawbacks that a great amount of memory capacity is needed and that it is difficult to store a large quantity of data. In addition, in the conventional data communication unit such as a facsimile apparatus of group 3 or the like, in the case of storing the received data in the buffer memory, after the encoded data has been demodulated, it is transferred as is to the buffer memory, again resulting in the drawbacks that a great amount of memory capacity is required and that it is difficult to store a large quantity of data. Furthermore, this means that in the case where there is a limitation for the memory capacity, the transmission has to be interrupted at the time of overflow of the memory, which causes the acquisition time of the lines to become long.